1. Field of the Invention
The present invention relates to a digital video playback apparatus in a digital video device and method therefor, and more particularly, to a digital video playback apparatus for playing-back the video and audio signals that have been recorded by using a plurality of cameras at different angles and method therefor.
2. Description of the Related Art
As illustrated in FIG. 1, in the case of taking a motion picture or a music video, a camera is set in front of an object and four microphones SL (Surround Left), SR (Surround Right), FL (Front Left), and FR (Front Right) are set surrounding the object to secure the presence of the sounds. The audio and video signals from the camera and the microphones are recorded, on a recording medium such as a disc, by a known video recorder illustrated in FIG. 2.
Referring to FIG. 2, a multiplexer (MUX) 14 receives system information which includes the number of video blocks, the number of audio blocks, a start address for each of the video blocks, and a start address for each of the audio blocks. A video encoder 10 converts an analog video signal input into digital video data, and formats the digital video data in a predetermined manner. The video data output from the video encoder 10 are applied to the multiplexer 14. An audio encoder 12 converts the 4-channel analog audio signals FL, FR, SL and SR from the microphones into digital audio data, and formats the digital audio data in a predetermined manner. The audio data output from the audio encoder 12 is transferred to the multiplexer 14. As illustrated in FIG. 3, the multiplexer 14 generates by turn the system information, the video data, and the audio data. A digital recorder 16 records, by turn, the system information, the video data, and the audio data on the recording medium.
FIG. 4 illustrates a conventional video playback apparatus for playing-back the audio and video data recorded as shown in FIG. 3. As illustrated, a digital playback apparatus 20 reads out video and audio data which are compressed and recorded on the recording medium such as a disc. The read video and audio data undergo an error correction and deinterleaving process. A demultiplexer (DMUX) 22 separates a signal output of the digital playback apparatus 20 into the system information, the video data, and the audio data. A video decoder 24 decodes compressed video stream data output from the demultiplexer 22, to expand the compressed video stream data. The video decoder 24 may be realized by a chip CL480 or CL9100 manufactured by C-Cube Co. An NTSC (National Television System Committee) encoder 26 encodes a video signal output from the video decoder 24 into an NTSC video signal. The NTSC encoder 26 may be realized by a chip CXA1145P manufactured by Sony Co., or a chip KA2194D manufactured by Samsung Electronics Co. An audio decoder 28 decodes the compressed audio stream data output from the demultiplexer 22, to expand the compressed audio stream data into the 4-channel audio data. A digital-to-analog converter and amplifier 29 converts the expanded 4-channel audio data from the audio decoder 28 into the original 4-channel analog audio signals FL, FR, SL and SR, and amplifies the converted 4-channel analog audio signals. However, since such a video playback apparatus reproduces the video signal from only one camera, it is not possible to reproduce a video signal from another camera at a different angle.
It is therefore an object of the present invention to provide a digital video playback apparatus capable of selectively reproducing video signals which are recorded by using a plurality of cameras each at different angles.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
The above and other objects of the present invention are achieved by providing a digital video playback apparatus which includes a digital playback apparatus to read out first and second video steam data and audio stream data, which are compressed and recorded on a recording medium, the first and second video stream data and the audio stream data undergoing an error correction and deinterleaving process; a demultiplexer to separate a signal output of the digital playback apparatus into system information, the first and second video stream data, and the audio stream data; first and second video decoders to expand the first and second compressed video stream data outputs from the demultiplexer, respectively; an audio decoder to decode and expand the audio stream data output from the demultiplexer; a key input section to generate first and second angle selection signals; a controller to analyze the system information from the demultiplexer and the angle selection signals from the key input section, to generate a switching control signal, a plurality of delay time control signals, and a plurality of gain control signals; a switch to select the first and second video stream data outputs from the first and second video decoders according to the switching control signal; and a delay time and gain control circuit to delay the 4-channel audio stream data outputs from the audio decoder according to the delay time control signals, and control gains of the delayed 4-channel audio stream data according to the gain control signals.